'Blackfish': The film SeaWorld would rather you not see

It was the third death Tilikum played a role in and one of many deaths and injuries caused by killer whales in captivity over the years.

Those stories are told in
Gabriela Cowperthwaite's documentary
"Blackfish," which makes its television debut Thursday, Oct. 24, on CNN.

A Grand Jury Prize nominee at this year's Sundance Film Festival, "Blackfish" features many former SeaWorld trainers who recall their childhood dreams of working with whales and dolphins and the love and respect they developed for the animals.

"When you look into their eyes, you know somebody is home," says former trainer
John Jett. This is not naive anthromorphism on his part -- an MRI of an orca's brain reveals a highly developed paralimbic system, suggesting that orcas not only are highly intelligent but also have rich emotional lives.

While that makes them trainable, it also makes them "ticking time bombs," according to neuroscientist
Lori Marino.

"All whales in captivity have a bad life," she says in the film. "They're all emotionally destroyed; they're all psychologically traumatized."

Before Brancheau, Tilikum was implicated in the deaths of
Keltie Byrne, a trainer at the Canadian marine park where he lived before coming to Orlando, and
Daniel P. Dukes, a SeaWorld visitor who had stayed after hours and sneaked into the orca tank. Despite this pattern of aggressive behavior, he continued to be used for his primary purpose at SeaWorld: breeding. Fifty-four percent of the park's orcas have Tilikum's genes, according to former trainer
Samantha Berg.

The film ends with several of the ex-trainers on a whale watch, where they observe orcas in the wild. It's an emotional moment that reinforces the film's message: There's no place like home, and home should not be a tank.